It has been reported that the average urban commuter spends roughly thirty six hours per year in traffic jams. This figure corresponds to the average American work week. Therefore, the economic impact of such wasted time is in the billions of dollars each year. While harder to quantify, the social and emotional toll of traffic jams are also significant.
Various systems have been developed in an effort to ease traffic congestion and reduce time wasted in traffic jams. One such system involves measuring traffic speed along a given route to calculate an estimated travel time. Real-time data regarding travel time can then be overlaid on a map to create a visual indicator of which roadways are moving the fastest. However, this method provides a relatively inaccurate estimate for several reasons. Travel time between two points is a calculation of when a global positioning system (or other location device) indication identifies the spatiotemporal status of a vehicle, or probe, and compares it to a subsequent spatiotemporal measurement. Travel time between the two spatial (location) points is then estimated. Due to the nature of probe estimations, the route could have been compromised by a stop made by the probe vehicle or a detour on a similar route to avoid an incident resulting in a false report of travel time along the assumed route.
Further, while immediate reporting of a GPS-tracked probe vehicle's speed can be helpful to determine the traffic flow on a particular segment, it cannot be used to measure traffic volume—a key determinate of how well an arterial road is performing. If the tracked vehicle pulls to the side of the road, or stops to pick up dry cleaning on the way home, the probe system may mistake it for an incident if no other probes are flowing past that area at that moment.
Therefore, a need exists in the art for a system capable of accurately measuring both vehicle speed and traffic volume, in order to accurately calculate not only travel time along a given segment of road, but also the general health of the assumed route as well. To satisfy this need for volume, the intersections along the routes will be used. A system that properly measures the health of a network of intersections; through both speed and volume can more accurately determine the impact on the route between them.